But for any riders who missed that memo, enter Professor Muni — a hardhat-toting and stick-wielding character who explains the boarding change in a professorial accent. He’s played by Mark DeAnda, an employee with Municipal Transportation Agency’s communications team, according to the department’s spokesman Paul Rose.

For a particularly silly yet effective explanation of all-door boarding, skip ahead to the two-minute mark, where the Professor acts out a walking, talking Clipper Card and two $1 bills hopping on a model bus at the appropriate entrances.